Mitering tube



y f. 2s, 19241 1,513,100

C. H.FREDERICK MITERING TUBE Filed Aug. 10. 1923 2 Shntlj'gnhnt. l

Get. Z8 1924.

' c:.- H. FREDERICK MITERING TUBE 2 Sheets-Sheet 2 Filed Aug. 10 1923 Patented ct. 28, 1924.

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CLARENCE H. FREDERICK, or xnnosnnwrsconsin, Assienoa 'rovsiMMoNs Coivii PANY, or KENosEA, wisconsin, A coEroEAfrioiqoE DELAWARE.

' Miramare TUBE.

Application filed August 10, 1923. Serial No. 656,688.k

To all whom t may concern: y

Be it known that I, CLARENCE H. FRED- ERICK, a citizen of the United States, residing at Kenosha, in the county of Kenosha and Statey of lVisconsin, have invented cert-ain new and useful Improvements in Mitering Tubes, of which the following is a specification.

My invention relates to improvements in mitering tubes and has particular reference to the method of cutting a il-shaped notch in the side of a length of tubing in order to l .be convenient-ly practiced by the use of comparatively simple and inexpensive cutting devices 'or dies; to provide a process which can be depended upon to turn out accurate work and which will not buckle or distortr the tubing subjected to said process; to provide an improved apparatus for carrying out said process and in general to provide a simple, economical and eflicient process and apparatus of the' character referred to.

Referring to the drawings which illustratey my invention as applied to the cutting of a V-shaped notch in the side of a length of light weight steel tubing of rectangular cross section,

Fig. l is a plan view of the lower die equipment for performing the first operative ste s f Fig. 2 is a front elevation of the parts shown in Fig. 1 and also showing the punch.

Fig. 3 is a section taken on the line yequipment for performing they second andy third operations."y

Fig. 'l' is a sectionitaken on the linetZ'V- l of Fig. 6.

Fig. 8 is a sectiontalten onl the line j 'of Fig. 6.

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Fig. 9 is aperspective viewy of the length of tubing after all of the cutting operations have been performed thereon, andy j Fig. l() is a perspective view showing the tube after it has'vbeen bent to bringthemh tered edges together, forming an angulary corner or bend therein.

Heretofore, ysoir far as I am aware, it yhas been the usual practice when forming miters in tubing, to fuse separate'findependent lengths of tubing, the ends of which have been suitably beveled'by rvsawing or otherwise, vto make them tthe adjacent 'corre-y spondingly `cut end of the adjoining tube section. It will be manifest that this method, although it can be carried out with great speed and with comparatively simple sawing equipment, involves yconsiderable `difliculty when the mating ends oftheltube sections are joined together. In the first place, it is often difficult to `hold the'tube lengths at the proper angle, and in the same common plane when they are being united together by welding brazing or otherwise and inthe second place,xunless extraordinary carey be taken to saw the several parts ofthe finished miter structure from the same length or the same batch of tubing, there is a possibility that variations in the size of the tubing may cause badly fitting corners or corners which require special 'operations after unionin order to bring them to 'the desired state of lit and finish. n f y i I am aware thatattempts have ybeen made to remove V-shaped portionsof-"nietal-l from the` sides of metal lengthsfin orderthat they may be bent to form such mitered joints, but so far as yI am advised, no one has attempted or ybeen ableto cuty such notches simply andeconomically by means of Apunch and die equipment. f

In order to secure maximum simplicity of, operation and equipment, II rprefer o divide my improvedprocess into three steps. The first step of the process involves theycutting of an opening,usually reetangulanrinone of the side walls of the tubing, `said side wall bein@v referabl removed Afor ,ay distance equal to the length 'of the base of thek V- the finish oi' this operation leaving the tub-y ing in the ncondition shown in Fig. 9.

Referring to the drawings 1n which lt1 y l, 2,3 and4 show the equipment lfor lperforming the first operation, 2O indicates the baseer shoe upon which the lower die equipment is mounted. Said equipment includes a guide str1p2l on one side, and spaced guide blocks 22 and 23 en the other side Y. theupward drag of the punch 28.

forming' a groove or slot vfor receiving thc tube length 24. Cross strips 25 and 26 held down by means such as cap screws 27, serve to hold downV the tube against- A Said punch 28 is carried on the lower end ot the yusual stemor shank 29 which is clamped in the ,reciprocating member or head of the press and is made with a substantially rectangular back portion 30 arranged to sli le behind and be sustained by an abutment 3l secured to the upper surface of shoe 20. .The blocks 22 and 23 which, beside serving as guides, also-participate in the Vcutting operation, are made with vertically extending cutting edges ,32 and 33 and areA spaced apart to slidably receive the punch `28. A

v ln Fig. 4, I have illustrated the plug die 34 whichy comprises a length of steel ot rectangular cross section of suitable dimensionsto lit snugly the interior of the tube length 24, the :tree end 35 of said plug die 34,-being beveled as indicated at 36 so that the end of the tube 24 will freely slip over the. end of said plug. Said plug 34 supported at its lixed end by means ot a stemcomprisino a stout rod 37 secured or fixed against longitudinal movement in any suitable manner and upon any suitable stationary portion of the press bed.

Said plug die 34 has its side cut away to correspond with the shape et the openin'o, desired in the sideof `the tube as in,-v

descend, the side wall of the tube will be sheared away by reason of the side edges oi' the punch cooperating with the cutting edges 32 and 33, previously referred to.

The shearing oi' the lower edge 5l of the notch and the short beveled edges and 53 is performed by the cutting edges 42, 45 and 46 of the punch cooperating with a lower die member indicated best at 54 in Fig. 3, upon which the bottom face wall ot the tube 241 is supported and which is notched out in a manner similar to;l thev interior plug die 34. Thus, when the punch has completed its downward stroke, there has been removed from the side wall oiv the tube 24 alcompiete section of its length and there are also removed from theupper face wall 35 and lower face wallv 56, sections oi metal of shape substantially the same as that et the notch 38 in the plug die 34. This leaves the tubing in condition for the next two or final steps of the process.

For completing the notch in the opposite iacewalls and 560i the tube, comparatively simple die equipment is employed. Referring to Figs. 6, 7 and 8, 57 is the base or shoe which carries the lower die eansand, as shown best in Fig'. 8, is somewhat L-shaped in vertical cross section so as to provide an upstanding ledge part 58. @n said ledge part there is clamped a horizontally extending die member having a rectangular shank 59 and a cutting portion 60 which is V-shapedin plan and extends inwardly of the extension 58 so to project into the channel portion 6ly of the lowerdie member.

The shank 59 is clamped in position by a suitable block 62 and bolts or screwsv63, and the other wall of the channel 6l A is formed by an abutment member 64 which takes the form of a rectangular block interloclred with the base 57 and secured thereto by means of screws as at 65. The upper die member is mounted upon the usual shank 66 which carries a cutting meinber 67 made in the form otra rect-angular block having formed in one, side thereof a V-shaped cutting edge adapted to cooperate with the V-shaped cutting edge o the stationary die 60. t

When the upper or reciprocating die is elevated into its normal position, the tube may be introduced into the channel'l'between the point 68 of the stationary die 60 and the vertical wall 69 of abutment 64, whereupon the tube is then moved transversely so as to cause the point of stationary die member 60 to enter the rectangular notch or opening in the side Wall 50 of the tube.

The dimensions and angle of said V-shapedy die member 60 are such that7 as indicated in Fig. 6, the sidesof the die will engage the vertical edges of said opening while leaving the actual point 68 of the die barely in contact with the opposite or outer side wall 7 0 of the tube, the edges o-f the V constituting in effect continua-tions of the beveled edges 48 and 49 (see Fig. 5). It `will be understood that the vertical depth of the die block 60 is slightly less than the interior vertical dimension of the tube so that the die 60 will enter said tube freely. By further reference to Fig. 8, it willy be seen that in the lower end of the die block 67 there is bolted or otherwise secured a depending extension 71 which is of the proper distance to fit between the outer wall 70 of the tube and the vertical wall 69 of abutment 64. The inner edge 7 2 of said eX- tension 7l is preferably rounded or beveled slightly as shown in Fig. 8 so as to crowd the tube toward the shank 59 of die 60 and thereby insure accuracy in the cutting operation when the cutting edge 7 3 of die 67 later engages the face wall of the tube.

It will be manifest that when the press is tripped the die 67 will engage the face wall of `the tube and in cooperation with the cutting die 60 which supports the V-shaped portion 74, will effect severance of said last named -section of metal completing the for mation of the V-shaped notch in the upper face wall of the tube. Upon return of the head of the press to its normal elevated position, the tube is turned end for end and replaced on die so that when the press is tripped a second time a similar V-shaped portion of metal will be removed from the lower face wall 56 of the tube. Said tube then in the condition shown in Fig. 9 and the process of cutting the V-shaped notch therein is hence complete. Said tube may then b-e bent along dotted lines 75 by any suitable means so as to complete the formation o-f the miter joint, as indicated in Fig. 10, said joint being `subsequently welded or brazed together to fill up the same and unite the edges thereof securely togethen The described details of the process and equipment being illustrative of merelyfone phase of my invention, the scope of same` should be determined by reference to the appended claims, said claims being construed as broadly as possible, consistent with the state of the art.

I claim as my invention:

l. The nrethody of forming a V-shaped notch at a point intermediatethe length of a tube having a rectangular cross section preparatory to' bending same to form` an angle or miter therein, which consists yin first cutting away onek yof the side wallsy of the tube to form a yrectangular opening therein,.then inserting die means intofthe tube and then effecting relative movement of said means and external cooperating die means to remove Vshaped sections of metal from the opposite walls of the tube ad-v joining said opening.

2. The ymethod of forming a V-shaped notch at a point intermediate the length ofy a tube having la rectangular cross section preparatory tobending same to form an angle or miter therein, which consists in first cutting away one of the side walls of the tube toy form a rectangular opening therein, then inserting a' V-shaped die block through said 'opening and then effecting relative movement of said block and a co operating V-shaped cutting die to remove V-shaped sections of metal from the opposite walls of the tube adjoining said opening.

3. Apparatus for the purpose described comprising in general a horizontally extending self-supporting die member of V-shaped cross section, a `vertically reciprocating die member cooperating with said rst mentioned die member, and means on the lower end of salidfsecond die member for cooperating with a tubular membery supported by the Vfirst die member for holding a tube in position on said iirst mentioned die member.

4 CLARENCE H. FREDERIGK, 

